vaccum leak/intake

98 4.0 pushrod has 217000 miles has had p0171/p0174 codes during the colder months (goes away during summer) now it has started to miss while stopped at lights or stop signs and is throwing P1151 and P1152 codes. I have replaced all the sensors (except oxygen) and the intake gaskets. My next step is the intake gaskets, just want to make sure this is logical because the missing bothers me along with the p1151 and p1152 codes. any suggestions?

whens is the last time you tuned it up? if you put new plugs and wires on it and still dose it do a compression tes also.

I have replaced all the sensors (except oxygen) and the intake gaskets. My next step is the intake gaskets,

Let's first clarify, were the gaskets replaced or not? :grinyes: lol

my bad, no I have not replaced intake gaskets and yes I have replaced plugs and plug wires recently...I have not replaced coilpack though.